#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

int main(int argc,char **argv){

	int fdSrc;
	int fdDes;

  	if(argc != 3){
	
		printf("pararm error!\n");
		exit(-1);	
	}

	fdSrc = open(argv[1],O_RDWR);

	int size = lseek(fdSrc,0,SEEK_END);
	lseek(fdSrc,0,SEEK_SET);

	char *readBuf = (char*)malloc(sizeof(char) * size + 8);
	int n_read = read(fdSrc,readBuf,size);
	
	fdDes = open(argv[2],O_RDWR|O_CREAT|O_TRUNC,0600);	
//	ssize_t write(int fd, const void *buf, size_t count);
	int n_write = write(fdDes,readBuf,strlen(readBuf));
	if(n_write != -1){
		printf("write %d byte to file\n",n_write);
	}

	close(fdSrc);
	close(fdDes);

	return 0;
}
